The validation pipeline: which layer catches which mistake
Here is the thing nobody tells you about template errors: most of them are easy once you know who is complaining. Fibe doesn't validate your template in one big pass. It runs a series of layers, each one authoritative for a narrow scope, each one with its own vocabulary. A YAML parser and a launch API say "this is wrong" in completely different dialects. If you can read an error and instantly think "ah, that's the schema layer" or "that's the compiler, not the schema," you stop guessing and start fixing.
This guide walks the layers in order, shows you the exact class of mistake each one catches, and gives you the smallest change that makes it green. The theme throughout: Fibe fails fast and fails specifically, and the earlier a layer catches your problem, the cheaper it is to fix.